1. Field of the Invention
The present invention relates to an inductive chip link technique.
2. Description of the Related Art
A chip-on-chip (CoC) technique is well known as a technique of realizing miniaturization and increased speed of an LSI. In the CoC technique, chips having different functions are stacked and accommodated in a single package.
In CoC, an electrical connection between chips is established by a bump or a bonding wire. One of the problems with CoC is that electrical connections cannot be established by bumps alone when more than two of chips are accommodated in a package, and there are a decrease in performance and an increase in production cost as the number of chips increases.
In order to solve the problem, a technique of transmitting a signal between the stacked chips via radio has been developed as an improved CoC technique (for example, see Jpn. Pat. Appln. KOKAI Publication No. 2005-228981).
In the specification, the technique is referred to as “inductive chip link” (ICL), and a chip used in the technique is referred to as an “inductive chip”.
In ICL, for example, because the signal is transmitted between the chips accommodated in a package by electromagnetic induction, even if three or more chips are accommodated in the package, bonding wires are not required to electrically connect the chips. Therefore, there is no decrease in performance or increase in production cost even if the number of chips accommodated in a package is increased.
For this reason, ICL is very promising as a technique applicable to multifunctional electronic devices in the near future.
However, in cases where ICL is applied to an actual product, it is necessary to study specifications, such as radio signal intensity (signal transmission distance), signal transmission path, and layout of transmission/receiving antennas, which are suitable for the product.